Magnetic Nanotransducers in Biomedicine

Abstract

Owing to their abilities to identify diseased conditions, to modulate biological processes, and to control cellular activities, magnetic nanoparticles have become one of the most popular nanomaterials in the biomedical field. Targeted drug delivery, controlled drug release, hyperthermia treatment, imaging, and stimulation of several biological entities are just some of the several tasks that can be accomplished by taking advantage of magnetic nanoparticles in tandem with magnetic fields. The huge interest towards this class of nanomaterials arises from the possibility to physically drive their spatiotemporal localization inside the body, and to deliver an externally applied stimulation at a target site. They in fact behave as actual nanotransducers, converting energy stemming from the external magnetic field into heat and mechanical forces, which act as signals for therapeutic processes such as hyperthermia and controlled drug release. Magnetic nanoparticles are a noninvasive tool that enables the remote activation of biological processes, besides behaving as formidable tracers for different imaging modalities, thus allowing to simultaneously carry out diagnosis and therapy. In view of all this, owing to their multifunctional and multitasking nature, magnetic nanoparticles are already one of the most important nanotechnological protagonists in medicine and biology, enabling an actual theranostic approach in many pathological conditions. In this Concept, we first provide a brief introduction on some physical properties of magnetic materials and on important features that determine the physical properties of magnetic nanoparticles. Thereafter, we will consider some major biomedical applications: hyperthermia, drug delivery/release, and nanoparticle-mediated control of biological processes, even at subcellular level.

Infrared‐Emitting Multimodal Nanostructures for Controlled In Vivo Magnetic Hyperthermia

“…[ 12,13 ] The deep penetration of magnetic fields within the human body, together with the possibility of targeting MNPs to specific tissues, have enabled minimally invasive, local, and remotely activated heating showing high efficacy at the in vitro and in vivo levels. [ 14–23 ] Clinical trials have shown the efficacy of MHT to treat solid tumors, as well as to increase the usefulness of chemotherapy by enhancing drug permeability of cancer tissues. [ 24,25 ] Reaching high standards of efficacy and selectivity in MHT treatments requires full control over the remote heating process, which means precise localization of the MNPs and real‐time thermal feedback into the treated tissue.…”

Nutlin-Loaded Magnetic Solid Lipid Nanoparticles for Targeted Glioblastoma Treatment

“…Although targeted delivery by nanocarriers can increase the amount of drug at the brain level, the accumulation to the tumor site can however result quite limited [25]. A solution for focusing drug-loaded nanoparticles to a specific area of the organism is offered by the exploitation of magnetically responsive nanostructures, that can be directed toward target sites through the use of magnetic fields produced, for example, by external static sources like permanent magnets [26]. In this view, the present study proposes a nanotechnological solution to increase the possibilities of treatment against GBM.…”

Lipid‐Based Nanocarriers for The Treatment of Glioblastoma

“…On one side, we can take advantage of the lipid-based nanoparticle features, such as the high drug payload, the better targeting, and the improvement in terms of systemic toxicity of the treatment. On the other side, we could benefit from the magnetic nanoparticle characteristics: [ 128 ] they can be used for imaging as contrast agents in magnetic resonance imaging (MRI), [ 129 ] to perform physical targeting, [ 130 ] and to induce magnetic hyperthermia [ 131 ] applying an alternate magnetic field (AMF), and thus inducing a local temperature increment. This increased temperature can be beneficial for different purposes, such as the controlled drug release using temperature-sensitive nanomaterials.…”